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Previously, Whipp et. al. (J. Appl. Physiol.: Respirat. Environ. Exerc. Physiol. 50(1):217-221, 1981) demonstrated the feasibility of determining four parameters of aerobic function, identified as maximum oxygen uptake (μVO_2), VO_2 at anaerobic threshold (θan), the time constant for oxygen uptake kinetics (rVO_2) and work efficiency (η), using a short duration ramped bicycle ergometer exercise test. Because of the importance of being able to measure these parameters on a variety of measurement instruments a short duration ramping treadmill protocol has been developed. The ability of this protocol to determine the four aerobic parameters has been validated against conventional methods. The results of this investigation indicate that μVO_2, θan, rVO_2 and, η may be obtained from a single, short-duration ramping treadmill test.

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The diploma thesis is focused on the design of water antigravity treadmill, which is unsatisfactory for current products, and has shortcomings in terms of ergonomics. Design of the device takes into consideration the connection between water and man and, also the ergonomic requirements for all users. The design was significantly influenced by the choice of materials, which enabled round shaping of the device. A technical innovation is the built – in wheelchair access ramp. The device is multi – purpose, suitable for a wide range of patients and athletes. Thanks to the built – in ramp, space requirements had been significantly reduced.

Running injuries are common, usually causing athletes to cease or significantly reduce participation in a particular sport. The recent development of aquatic treadmills (ATM), an alternative to land treadmill (LTM) running, provides another option. This study sought to examine the metabolic (VO2) relationship between varying jet resistances and running speed on an ATM versus LTM. This was accomplished by developing two linear regression equations and a prediction equation. One linear regression represented the predicted VO2 from a given speed and jet resistance setting in the water, the other linear regression predicted VO2 on land from a given speed and the prediction equation was designed to match land speed to a VO2 score derived from ATM running conditions. This study examined experienced runners (N = 18). Each subject completed an initial VO2 peak test, three LTM trials, and 18 ATM trials. Each ATM trial consisted of running for three minutes at either a relatively slow, moderate, or somewhat fast speed while one of six ATM jet settings ranging from 0 to 100% jet capacity in 20% increments were assigned to the trial. Oxygen consumption (VO2) and heart rate (HR) were measured during each trial while ratings of perceived exertion (RPE) were solicited immediately following each trial. Resulting analysis produced an ATM linear regression for each jet resistance setting and a LTM linear regression equation of VO2 = 4.16 * speed + 7.39. A prediction equation for each jet resistance setting was then determined from the linear regression equations for both the ATM and LTM conditions. Results showed that at and between 0-40% jet resistances that there is not a marked difference in metabolic cost but from 40-100% jet resistances the VO2 is influenced more strongly. These results demonstrate that ATM metabolic costs are not only influenced by jet resistance settings but at jet resistances of 40% or greater provide an intensity of exercise that mimics running faster on LTM. This provides an added benefit for those individuals who may be limited due to acute overuse-type injuries or returning to full LTM activity following lower extremity surgery.

An attempt was made to evaluate the applicability of a theorized model concerning plasma lactic acid kinetics to running performance assessment. This model incorporated two distinct lactate thresholds identified as the aerobic threshold (AerT) and the anaerobic threshold (AT). Two groups of males with different levels of fitness were tested. Group 1 (n = 5) consisted of recreational athletes (͞X VO₂ max = 49.3 ml/kg•min⁻¹) who ran less than 20 miles per week, while Group 2 (n = 6) were highly trained runners (͞X VO₂ max = 65.5 ml/kg•min⁻¹) who all ran at least 40 miles per week. All subjects participated in two incremental work load (IWL) and four constant work load (CWL) tests that consisted of horizontal treadmill running at different speeds. The IWL tests elicited linear increases in VO₂ and were highly correlated for both Group 1 (r = .986) and Group 2 (r = .999). However, three unbiased observers found the identification of both AerT and AT, using independent lactate and respiratory gas exchange "breakpoints," very subjective in nature. The test-retest reliablity was generally poor and varied considerably among both the observers and the individual predictor variables. The validity of the respiratory gas exchange predictors was then evaluated against the criterion lactate thresholds using the estimates of a fourth, more experienced observer. The resultant correlation coefficients were generally not high, while t-test evaluation demonstrated significant (p < .05) differences in fifty percent of the cases. This same observer then pooled all of the ventilatory predictors in an effort to better estimate both AerT and AT indirectly. These indirect ventilatory estimates consistently underpredicted the criterion lactate thresholds. This finding suggests that increases in running speeds may confound the normal associate between plasma lactate and ventilation at increasing work levels. Arbitrary lactate concentrations of 2mmol/2 and 4 mmol/L were further evaluated as threshold predictors. This methodology consistently overpredicted the criterion lactate thresholds in terms of VO₂. When any of these AerT and AT threshold estimates were compared to the lactate responses during the appropriate CWL test, no meaningful relationship were found. These observations question the physiological significance of both AerT and AT evaluation during treadmill running, as well as pointing out the difficulty in reliably detecting both plasma lactate thresholds regardless of the methodology.

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There were two primary goals in this investigation. The first goal was to determine if inter-individual variability in time to exhaustion at the velocity associated with V02max (Tlim at Vmax) was explained by anaerobic capacity (AC), Vmax, anaerobic threshold (AT), and/or a combination variable in the form [AC • (Vmax - vAT)^-1]. The second goal was to determine if AC could be predicted from Tlim at Vmax, AT, and/or a combination variable in the form [Tlim • (Vmax - vAT)].

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